Transcatheter vs surgical aortic valve replacement in intermediate-surgical-risk patients with aortic stenosis: a propensity score-matched case-control study

BACKGROUND

Limited real-world data comparing outcomes after transcatheter (TAVR) and surgical aortic valve replacement (SAVR) in intermediate-surgical-risk patients with aortic stenosis are available.

METHODS

We identified 182 consecutive patients who underwent TAVR via the transfemoral (TF) route (November 2007-February 2011) and 111 moderate-to-high-risk historical case controls undergoing SAVR (August 2003-July 2008). Using propensity score matching based on clinical characteristics and surgical risk scores, we compared clinical outcomes in 111 matched patients. Valve Academic Research Consortium definitions were applied for end point adjudication.

RESULTS

Baseline clinical characteristics, in particular Logistic European System for Cardiac Operative Risk Evaluation (23.2 ± 15.1 vs 24.4 ± 13.4) and Society of Thoracic Surgeons score (4.6 ± 2.3 vs 4.6 ± 2.6), were well matched between groups. Transfemoral TAVR was associated with more vascular complications (33.3% vs 0.9%, P < .001). On the other hand, acute kidney injury was more frequent after SAVR (8.1% vs 26.1%, P < .001). The rates of all-cause mortality in both TF-TAVR and SAVR groups was1.8% at 30 days (P = 1.00) and 6.4% and 8.1%, respectively, at 1 year (P = .80). At 1 year, the rate of cerebrovascular events was similar in the 2 groups (4.6% vs 9.1%, P = .19).

CONCLUSIONS

In this real-world cohort of intermediate-surgical-risk patients with aortic stenosis, TF-TAVR and SAVR were associated with similar mortality rates during follow-up but with a different spectrum of periprocedural complications. Furthermore, the survival rate after TF-TAVR in this group of elderly patients with intermediate Society of Thoracic Surgeons score was encouraging.

Cardiac conduction system disease after transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) is a rapidly-evolving technology for patients with severe, calcific aortic stenosis. Although these procedures lessen many of the risks and complications of open surgical aortic valve replacement, there remain challenges with TAVR including electrophysiologic complications. Among TAVR prostheses, rates of conduction abnormalities (CAs) vary from less than 10% to more than 50%, with up to one-third of patients requiring placement of a permanent pacemaker following TAVR. Several predictors of CAs have been identified related to device selection, baseline conduction defects, and anatomical considerations. Current data support the hypothesis that CAs result primarily from mechanical compression of the specialized conduction system by the device, although other factors may be involved. Such abnormalities can arise immediately during the procedure or as late as several days after implantation, and can be transient or permanent. Currently, there are no clinical tools to identify patients at highest risk for CAs post-TAVR, or to predict the course of CAs in patients who experience them. Early data suggest outcomes may be worse in high-risk patients, and further studies are needed to identify these patients so as to minimize electrophysiologic complications and determine appropriate monitoring in this expanding population.

Image-guided transapical aortic valve implantation: sensorless tracking of stenotic valve landmarks in live fluoroscopic images

OBJECTIVE

Aortic valve stenosis is one of the most frequently acquired valvular heart diseases, accounting for almost 70% of valvular cardiac surgery. Transapical transcatheter aortic valve implantation has recently become a suitable minimally invasive technique for high-risk and elderly patients with severe aortic stenosis. In this article, we aim to automatically define a target area of valve implantation, namely, the area between the coronary ostia and the lowest points of two aortic valve cusps. Therefore, we present a new image-based tracking method of these aortic landmarks to assist in the placement of aortic valve prosthesis under live 2D fluoroscopy guidance.

METHODS

We propose a rigid intensity-based image registration technique for tracking valve landmarks in 2D fluoroscopic image sequences, based on a real-time alignment of a contrast image including the initialized manual valve landmarks to each image of sequence. The contrast image is automatically detected to visualize aortic valve features when the aortic root is filled with a contrast agent.

RESULTS

Our registration-based tracking method has been retrospectively applied to 10 fluoroscopic image sequences from routine transapical aortic valve implantation procedures. Most of all tested fluoroscopic images showed a successful tracking of valve landmarks, especially for the images without contrast agent injections.

CONCLUSIONS

A new intraoperative image-based method has been developed for tracking aortic valve landmarks in live 2D fluoroscopic images to assist transapical aortic valve implantations and to increase the overall safety of surgery as well.

Outcomes of patients with severe aortic stenosis at high surgical risk evaluated in a trial of transcatheter aortic valve implantation

Recent randomized clinical trials have demonstrated that transcatheter aortic valve implantation (TAVI) reduces mortality in high-risk patients with aortic stenosis who are not candidates for aortic valve replacement (AVR). In similar patients who are acceptable candidates for AVR, TAVI provides equivalent outcomes to AVR. In this study, 900 patients with severe aortic stenosis at high surgical risk were evaluated as possible candidates for TAVI. Of these, 595 (66.1%) had neither TAVI nor AVR and constituted the medical arm. In addition to the best available conservative care, 345 patients (39.3%) in this group had balloon aortic valvuloplasty. The AVR arm consisted of 146 patients (16.2%) and the TAVI arm of 159 patients (17.6%). The AVR group had significantly lower clinical risk compared to the medical and TAVI groups, with lower mean age, Society of Thoracic Surgeons score, and logistic European System for Cardiac Operative Risk Evaluation score. Patients in the medical and balloon aortic valvuloplasty group had significantly higher B-type natriuretic peptide levels compared to those in the AVR and TAVI groups and had, on average, lower ejection fractions. The medical and balloon aortic valvuloplasty group was followed for a median of 206 days; the mortality rate was 46.6% (n = 277). The AVR group was followed for 628 days; 39 patients died (26.7%). In 399 days of follow-up, the mortality rate in the TAVI group was 30.8% (n = 49). In conclusion, patients with severe AS who did not undergo TAVI or AVR had high mortality. In properly selected patients, TAVI and AVR improve outcomes. Renal failure is the strongest correlate for adverse outcomes, irrespective of treatment group.

[Transcatheter aortic valve replacement: when should it be used in aortic stenosis?]

30% of patients with significant aortic stenosis are not considered for operative aortic valve replacement because of the high perioperative risk. An alternative catheter based option for these patients is the transcatheter aortic valve replacement (TAVI). In general, there are two approaches for TAVI: transfemoral and transapical. Transfemoral aortic valve replacement is performed by transcatheter replacement of an aortic valve via the femoral arteries. Transapical valve replacement is achieved by transcatheter implantation via the fifth intercostal space. The most common complications are vessel injuries, bleeding complications, new onset of AV-block, development of paravalvular insufficiency, acute kidney injury, stroke and TIA. The first long-term observations suggest positive results. First clinical trials in a high-risk population show a promising outcome. Therefore TAVI offers a reasonable therapy option for patients with high perioperative risk. Further long-term clinical trials are still pending.

The impact of peripheral arterial disease on early outcome after transcatheter aortic valve implantation: results from the German Transcatheter Aortic Valve Interventions Registry

BACKGROUND

A significant proportion of patients undergoing transcatheter aortic valve implantation (TAVI) have concomitant peripheral arterial disease (PAD), which plays a crucial role in the preinterventional selection process of determining an optimal vascular access site. The aim of our study was to determine the impact of PAD on clinical outcome after TAVI in a real-world setting.

METHODS

A total of 1,315 patients (mean logistic European System for Cardiac Operative Risk Evaluation 20.6% ± 13.7%) underwent TAVI in 27 centers and were included in the prospective German TAVI Registry.

RESULTS

Of the 1,315 patients with TAVI, 330 (25.1%) had PAD. These patients had a higher logistic European System for Cardiac Operative Risk Evaluation score (27.7% ± 16.0% vs 18.3% ± 12.0%, P < .0001), mainly attributed to more frequent and severe comorbidities. Compared with patients without PAD, patients with PAD had a higher rate of vascular complications (28.5% vs 20.7%, P < .01), dialysis-dependent renal failure (11.2% vs 5.4%, P < .001), myocardial infarction (1.2% vs 0.3%, P < .05), and, subsequently, 30-day mortality (12.7% vs 6.9%, P < .001). Choosing a surgical approach, for example, transapical access, did not reduce the periprocedural risk associated with PAD; in-hospital mortality was 15.7% for surgical and 10.5% for percutaneous patients with TAVI having PAD (P < .001). In a multivariate regression analysis, PAD was an independent predictor of 30-day mortality (hazard ratio 1.8, 95% CI 1.2-2.7, P = .004) after TAVI.

CONCLUSIONS

In this real-world TAVI Registry, PAD was an independent predictor of mortality in patients with percutaneous and surgical TAVI, including vascular complications. Assessment of PAD should play a crucial role in the preinterventional selection process, regardless of the access strategy.

Transapical versus conventional aortic valve replacement--a propensity-matched comparison

INTRODUCTION

The goal of this study was to compare the short- and long-term outcomes after aortic valve (AV) surgery carried out via standard sternotomy/partial sternotomy versus transapical transcatheter AV implantation (taTAVI).

PATIENTS AND METHODS

All 336 patients who underwent taTAVI between 2006 and 2010 were compared with 4533 patients who underwent conventional AV replacement (AVR) operations between 2001 and 2010. Using propensity score matching, we identified and consecutively compared 2 very similar groups of 167 patients each. The focus was on periprocedural complications and long-term survival.

RESULTS

The 30-day mortality rate was 10.8% and 8.4% (P = .56) for the conventional AVR patients and the TAVI patients, respectively. The percentages of postoperative pacemaker implantations (15.0% versus 6.0%, P = .017) and cases of renal failure requiring dialysis (25.7% versus 12.6%, P = .004) were higher in the TAVI group. Kaplan-Meier curves diverged after half a year in favor of conventional surgery. The estimated 3-year survival rates were 53.5% ± 5.7% (TAVI) and 66.7% ± 0.2% (conventional AVR).

CONCLUSION

Our study shows that even with all the latest successes in catheter-based AV implantation, the conventional surgical approach is still a very good treatment option with excellent long-term results, even for older, high-risk patients.

Comparison of complications and outcomes to one year of transcatheter aortic valve implantation versus surgical aortic valve replacement in patients with severe aortic stenosis

Comparisons of transcatheter aortic valve implantation (TAVI) to surgical aortic valve replacement (SAVR) in patients with severe aortic stenosis remain sparse or limited by a short follow-up. We sought to evaluate early and midterm outcomes of consecutive patients (n = 618) undergoing successful TAVI (n = 218) or isolated SAVR (n = 400) at 2 centers. The primary end point was incidence of Valvular Academic Research Consortium-defined major adverse cerebrovascular and cardiac events (MACCEs) up to 1 year. Control of potential confounders was attempted with extensive statistical adjustment by covariates and/or propensity score. In-hospital MACCEs occurred in 73 patients (11.8%) and was more frequent in patients treated with SAVR compared to those treated with TAVI (7.8% vs 14.0%, p = 0.022). After addressing potential confounders using 3 methods of statistical adjustment, SAVR was consistently associated with a higher risk of MACCEs than TAVI, with estimates of relative risk ranging from 2.2 to 2.6 at 30 days, 2.3 to 2.5 at 6 months, and 2.0 to 2.2 at 12 months. This difference was driven by an adjusted increased risk of life-threatening bleeding at 6 and 12 months and stroke at 12 months with SAVR. Conversely, no differences in adjusted risk of death, stroke and myocardial infarction were noted between TAVI and SAVR at each time point. In conclusion, in a large observational registry with admitted potential for selection bias and residual confounding, TAVI was not associated with a higher risk of 1-year MACCEs compared to SAVR.

Surgical experience of ascending aorta and aortic valve replacement in patient with calcified aorta

Background

The conventional method of aortic cross-clamping is very difficult and increases the risk of cerebral infarct due to embolism of the calcified aorta in these patients. Accordingly, we analyzed our experience with 11 cases of ascending aorta and aortic valve replacement with hypothermic circulatory arrest.

Materials and Methods

From January 2002 to December 2009, 11 patients had ascending aorta and aortic valve replacement with hypothermic arrest at our hospital. We performed a retrospective study.

Results

There were 5 males and 6 females, with a mean age of 68 years (range, 44 to 82 years). Eight patients had aortic stenosis, and 3 patients had aortic regurgitation. An aortic cannula was inserted into the right axillary artery in 3 patients and ascending aorta in 6 patients. Two patients with aortic regurgitation had a remote access perfusion catheter inserted though the right femoral artery. The mean cardiopulmonary bypass time was 180 minutes (range, 110 to 306 minutes) and mean hypothermic circulatory arrest time was 30 minutes (range, 20 to 48 minutes). The mean rectal temperature during hypothermic circulatory arrest was 21℃ (range, 19℃ to 23℃). No patient had any new onset of cerebral infarct or cardiovascular accident after surgery. There was no hospital mortality. Early complications occurred in 1 patient who needed reoperation due to postoperative bleeding. Late complications occurred in 1 patient who underwent a Bentall operation due to prosthetic valve endocarditis. The mean follow-up duration was 32 months (range, 1 month to 8 years) and 1 patient died suddenly due to unknown causes after 5 years.

Conclusion

Patients with a calcified aorta can be safely treated with a technique based on aorta and aortic valve replacement under hypothermic circulatory arrest.

Transapical aortic valve implantation: incidence and predictors of paravalvular leakage and transvalvular regurgitation in a series of 358 patients

OBJECTIVES

The aim of this study was to evaluate the results when the surgical concept of not accepting intraprocedural paravalvular leakage was applied for transcatheter aortic valve implantation (TAVI).

BACKGROUND

The surgical strategy of conventional aortic valve replacement does not accept paraprosthetic leakage and requires immediate action to eliminate it. However, paravalvular leakage is the major concern after TAVI.

METHODS

A total of 358 patients underwent transapical TAVI with balloon-expandable prostheses. The modified procedural strategy consisted of precise positioning of the prosthesis using a modified TAVI technique and immediate additional intraprocedural treatment to eliminate relevant paravalvular leakage.

RESULTS

Balloon redilation of the transcatheter valve was performed in 18 patients (5%), and additional second valves were implanted in 13 (4%). At the end of the procedure, 186 patients (52%) had no paravalvular or transvalvular regurgitation. In the remaining 172 patients, paravalvular leakage was observed in 113 (32%), transvalvular leakage in 47 (13%), and both in 12 (3%). Leakage was trace in 88 patients (25%), mild in 82 (23%), and moderate in 2 (0.6%). Multivariate analysis identified male sex, New York Heart Association functional class IV, and no previous aortic valve replacement as predictors of post-procedural leakage. Cumulative survival was not dependent on post-procedural regurgitation rate. Overall mortality was 5 ± 1% at 30 days, 14 ± 2% at 6 months, 17 ± 2% at 1 year, and 33 ± 4% at 2 years.

CONCLUSIONS

The modified procedural strategy of transapical TAVI with a balloon-expandable prosthesis was associated with a low incidence of relevant prosthetic regurgitation.

Management of the Patient for Transcatheter Aortic Valve Implantation in the Perioperative Period

Aortic stenosis is a prevalent valvular disease among aging patients, and surgical correction is the most definitive treatment. Yet many elderly patients are deemed to be “inoperable” or at excessive risk to undergo open surgical aortic valve replacement (AVR). Transcatheter aortic valve implantation (TAVI), either through a transfemoral or transapical approach, has become a potential option for these high-risk patients. Although TAVI technology will continue to be developed and perfected, most studies at this time reveal that symptoms are improved and that 1-year morbidity and mortality are similar to those for open surgical AVR. Anesthetic management for patients undergoing TAVI involves maintaining hemodynamic stability during periods of rapidly changing conditions and providing echocardiographic guidance and assessment. Postoperative care includes a variety of challenges such as managing pain control, monitoring for potential complications, and providing hemodynamic management.

Transapical aortic valve implantation off-pump in patients with impaired left ventricular function

BACKGROUND

Patients with impaired left ventricular ejection fraction (LVEF) and severe aortic stenosis have a higher perioperative risk for aortic valve replacement. Transapical aortic valve implantation (TA-AVI) allows for off-pump valve implantation, which might be beneficial in the subgroup of patients with impaired LVEF.

METHODS

All patients with LVEF≤40% who underwent TA-AVI for severe aortic stenosis and who fulfilled at least 1-year follow-up formed the study group. Results were compared to TA-AVI patients with preserved LVEF treated during the same time period.

RESULTS

Thirty-nine patients with LVEF≤40% were identified, mean LVEF was 32.5±7.1%. Logistic EuroSCORE and STS-score were 43.6%±18.5% and 15.3%±9.3%, respectively. Concomitant coronary artery disease was present in 59% with 23.1% having had previous bypass surgery and 17.9% having had a history of prior myocardial infarction. Two patients required cardiopulmonary-bypass support due to intraoperative complications, and another 2 patients required cardiopulmonary-bypass for reperfusion. Median procedure time was 75 minutes (interquartile range, 65-90 minutes). LVEF at discharge increased significantly to a mean of 41.5%±10%, and at 1-year follow-up to 53.9%±13% (both p<0.0001). The proportion of patients in New York Heart Association class III-IV decreased from 92.3% to 15.0% at 1-year follow-up (p<0.001). There was neither a statistically significant difference in in-hospital mortality nor in long-term survival up to 4 years, in comparison to patients with preserved LVEF.

CONCLUSIONS

Transapical aortic valve implantation is a promising approach, allowing for off-pump treatment of elderly, high-risk patients with impaired LVEF requiring aortic valve replacement. Short-term and long-term outcomes are respectable, and an improvement in postoperative LVEF and New York Heart Association class can be anticipated.

Transcatheter aortic valve implantation or surgical aortic valve replacement as redo procedure after prior coronary artery bypass grafting

BACKGROUND

The perioperative risk for redo surgical aortic valve replacement (S-AVR) in patients with severe aortic stenosis and prior coronary artery bypass grafting (CABG) is increased. Transcatheter aortic valve implantation (TAVI) represents an alternative. We assessed the perioperative and mid-term clinical outcome of patients undergoing S-AVR or TAVI.

METHODS

In a retrospective observational, comparative study, 40 consecutive patients underwent redo operation with S-AVR or TAVI between April 2005 and April 2010. Median sternotomy and extracorporeal circulation were used for S-AVR; TAVI access was transfemoral (n = 27; 67.5%), transapical (n = 11; 27.5%), or transsubclavian (n = 2; 5.0%). Clinical and echocardiographic follow-up was at 30 days and 6 months.

RESULTS

TAVI patients were older (78.5 ± 6 vs 70.6 ± 8 years, p < 0.001) and presented higher logistic (33.5 ± 17 vs 20.2 ± 14, p < 0.001) European System for Cardiac Operative Risk Evaluation scores. All-cause mortality was 2.5% in both groups and major adverse cardiac and cerebrovascular event rates were comparable (7.5% TAVI vs 17.5% S-AVR, p = 0.311) after 30 days. TAVI was associated with a higher rate of permanent pacemaker implantation (30% vs 0%, p < 0.001) and grade II residual aortic regurgitation in 14%. Incidence of cerebrovascular events was 7.5% in S-AVR vs 2.5% in TAVI (p = 0.61).

CONCLUSIONS

In elderly, high-risk patients after prior CABG, conventional aortic valve replacement and TAVI are comparable treatment options with favorable clinical outcome. A redo operation itself does not sufficiently justify a TAVI approach.

The value of flat-detector computed tomography during catheterisation of congenital heart disease

OBJECTIVES

To analyse the diagnostic utility of flat-detector computed tomography imaging (FD-CT) in patients with congenital heart disease, including the value of image fusion to overlay three-dimensional (3D) reconstructions on fluoroscopic images during catheter-based interventions.

METHODS

We retrospectively analysed 62 consecutive paediatric patients in whom FD-CT was used during catheterisation of congenital heart disease. Expert operators rated the clinical value of FD-CT over conventional fluoroscopic imaging. Added radiation exposure and contrast medium volume were evaluated.

RESULTS

During a 12-month period, FD-CT was performed in 62 out of 303 cardiac catheterisations. Median patient age was 3.5 years. In 32/62 cases, FD-CT was used for diagnostic purposes, in 30/62 cases it was used in the context of interventions. Diagnostic utility was never rated as "misleading". It was classified as "not useful" in six cases (9.7%), "useful" in 18 cases (29.0%), "very useful" in 37 cases (59.7%) and "essential" in one case (1.6%). The median added dose-area product was 111.0 μGym(2), the required additional quantity of contrast medium was 1.6 ml/kg.

CONCLUSION

FD-CT provides useful diagnostic information in most of the patients investigated for congenital heart disease. The added radiation exposure and contrast medium volume are reasonable.

Transcatheter aortic valve implantation: patient selection and procedural considerations

Transcatheter aortic valve implantation has risen exponentially as a treatment modality for severe aortic stenosis in patients considered to be at high risk for or inoperable by conventional surgical aortic valve replacement. It has shown both survival and quality of life benefit in a randomized comparison to conservative (palliative) therapy in nonoperative candidates. Fundamental to its success is appropriate patient selection and a rigorous attention to procedural steps. In this article we will discuss the key issues pertaining to each of these factors.

Usefulness of TEE as the primary imaging technique to guide transcatheter transapical aortic valve implantation

OBJECTIVES

The aim of this study was to: 1) determine the usefulness of transesophageal echocardiography (TEE) as the primary technique to guide transapical (TA) transcatheter aortic valve implantation (TAVI); and 2) to compare TEE with angiography as the primary imaging modality for TA-TAVI guidance.

BACKGROUND

TEE has been routinely used as an adjunct to angiography during TA-TAVI procedures, but very few data exist on the use of TEE as the primary imaging technique guiding TA-TAVI.

METHODS

One hundred consecutive high-risk patients (mean age 79 ± 9 years, mean logistic EuroSCORE: 25.8 ± 17.6%) who underwent TA-TAVI in our center were included. The Edwards valve was used in all cases, and all procedures were performed in an operating room without hybrid facilities. The TA-TAVI was primarily guided by angiography in the first 25 patients (A-TAVI group) and by TEE in the last 75 patients (TEE-TAVI group). Procedural, 30-day, and follow-up results were evaluated.

RESULTS

No differences were observed between groups at baseline except for a higher (p = 0.001) prevalence of moderate or severe mitral regurgitation in the TEE-TAVI group. The procedure was successful in 97.3% and 100% of the patients in the TEE-TAVI and A-TAVI groups, respectively (p = 1.0), and a lower contrast volume was used in the TEE-TAVI group (12 [5 to 20] ml vs. 40 [20 to 50] ml, p < 0.0001). There were no differences between groups in the occurrence of valve malposition needing a second valve (TEE-TAVI: 5.3%; A-TAVI: 4%; p = 1.0) or valve embolization (TEE-TAVI: 1.3%; A-TAVI: 4%; p = 0.44). The results regarding post-procedural valve hemodynamic status and aortic regurgitation were similar between groups. The survival rates at 30-day and 1-year follow-up were 87% and 75% in the TEE-group and 88% and 84% in the A-TAVI group, respectively (log-rank = 0.49).

CONCLUSIONS

TEE-TAVI was associated with similar acute and midterm results as A-TAVI and significantly reduced contrast media use during the procedures. These results suggest the feasibility and safety of performing TA-TAVI procedures in an operating room without hybrid facilities, but larger studies are needed to confirm these findings.

A second prosthesis as a procedural rescue option in trans-apical aortic valve implantation

OBJECTIVE

Trans-apical aortic valve implantation (TA-AVI) using the Edwards SAPIEN™ prosthesis has evolved to a routine procedure for selected high-risk elderly patients. In rare cases, misplacement of the SAPIEN™ valve (too low a position), dysfunction of the leaflets or perforation of the interventricular septum (ventricular septal defect, VSD) occurs and requires immediate implantation of a second prosthesis within the first one. Results of this 'bailout' maneuver have not been reported yet.

METHODS

Of 305 TA-AVI procedures, 15 patients required a second prosthesis due to dysfunctional leaflets (n = 6), low position (n = 7), or VSD (n = 2). Mean age was 82.5 ± 1.3 years, mean logistic EuroSCORE (European System for Cardiac Operative Risk Evaluation) was 45.5 ± 5.4, and Society of Thoracic Surgeons (STS) Score was 13.5 ± 1.5.

RESULTS

All second SAPIEN™ valves could be implanted successfully within the first one. The second prosthesis solved leaflet dysfunction, sealed the VSD (lower position of the second prosthesis), or corrected the initial misplacement (higher position of the second prosthesis) in all patients. Within 30 days, four patients died (low cardiac output n = 3, all with preoperative ejection fraction (EF) <35%; intestinal ischemia n = 1). Intra-operative echocardiogram and angiogram revealed mild paravalvular leak in three and none/trace in 12 patients. Transvalvular gradients were low despite the implantation of the second valve (P(max)/mean 13.7 ± 4.3/6.4 ± 2.0).

CONCLUSION

Placement of a second SAPIEN™ valve is a valuable 'bailout' technique in case of VSD, dysfunctional leaflets, or too low placement of the first prosthesis. The technique leads to an excellent functional result with low transvalvular gradients. The simple, straight, tubular stent design of the SAPIEN™ prosthesis may be the ideal design for such valve-in-valve procedures.

[Transapical aortic valve implantation--indications, risks and limitations]

Calcified aortic stenosis is the predominant valve disease in the western world. Currently, surgical aortic valve replacement is the gold standard procedure for symptomatic severe aortic stenosis that can be performed with low morbidity and mortality. The prevalence of aortic stenosis increases with age, and the incidence of several comorbidities also unavoidably elevates the risk of surgical treatment. Therefore, the most adequate and gentle treatment is needed especially for this population. Since the first transcatheter aortic valve implantation (TAVI) was performed in 2002, the main implanting routes are the transfemoral, retrograde access through the common femoral artery, and the antegrade, transapical approach via anterolateral minithoracotomy. Meanwhile, TAVI has become an alternative treatment for patients who are not suitable candidates for surgical therapy in some centers.The initial clinical results are promising and have confirmed the feasibility of this technique. Due to the restricted long-term data, conventional aortic valve replacement still remains the standard for the treatment of aortic stenosis. Selection of the suitable therapy approach (surgical replacement, transfemoral or transapical aortic valve implantation) must consider each patient's specific risk profile and individual indication. Prospective, randomized trials will be necessary to assess the individual survival benefit of TAVI for various risk populations and to extend the indication.

Incidence, prognostic value and management of vascular complications with transfemoral transcatheter aortic valve implantation

Inoperable or high-risk patients with severe aortic stenosis who undergo transcatheter aortic valve implantation (TAVI) have better outcomes compared with those treated with standard medical therapy. As for any other invasive procedure, peri-procedural complications may occur, reducing the procedural success rate and potentially affecting short- and mid-term outcomes. The transfemoral approach prevails over other possible access-site options in most registries. The use of large introducer sheaths and the need for double arterial vascular access can lead to higher rates of vascular complications in this elderly population, with a high prevalence of baseline peripheral artery disease. In this article, we review the results of recent clinical trials and major registries using the two different bioprosthesis currently available for TAVI, focusing on access site-related complications with transfemoral TAVI, their management and relationship with in-hospital and 30-day survival. Awareness of the mechanisms behind these complications might help in their prevention, recognition and management and may ultimately improve the clinical outcome of TAVI procedures.

Injectable living marrow stromal cell-based autologous tissue engineered heart valves: first experiences with a one-step intervention in primates

AIMS

A living heart valve with regeneration capacity based on autologous cells and minimally invasive implantation technology would represent a substantial improvement upon contemporary heart valve prostheses. This study investigates the feasibility of injectable, marrow stromal cell-based, autologous, living tissue engineered heart valves (TEHV) generated and implanted in a one-step intervention in non-human primates.

METHODS AND RESULTS

Trileaflet heart valves were fabricated from non-woven biodegradable synthetic composite scaffolds and integrated into self-expanding nitinol stents. During the same intervention autologous bone marrow-derived mononuclear cells were harvested, seeded onto the scaffold matrix, and implanted transapically as pulmonary valve replacements into non-human primates (n = 6). The transapical implantations were successful in all animals and the overall procedure time from cell harvest to TEHV implantation was 118 ± 17 min. In vivo functionality assessed by echocardiography revealed preserved valvular structures and adequate functionality up to 4 weeks post implantation. Substantial cellular remodelling and in-growth into the scaffold materials resulted in layered, endothelialized tissues as visualized by histology and immunohistochemistry. Biomechanical analysis showed non-linear stress-strain curves of the leaflets, indicating replacement of the initial biodegradable matrix by living tissue.

CONCLUSION

Here, we provide a novel concept demonstrating that heart valve tissue engineering based on a minimally invasive technique for both cell harvest and valve delivery as a one-step intervention is feasible in non-human primates. This innovative approach may overcome the limitations of contemporary surgical and interventional bioprosthetic heart valve prostheses.

Transcatheter aortic valve implantation: evidence on safety and efficacy compared with medical therapy. A systematic review of current literature

OBJECTIVES

Transcatheter aortic valve implantation (TAVI) promises effective treatment for high-risk elderly patients with symptomatic severe aortic stenosis (AS). However, the adoption of TAVI must be justified and guarantee long-term performance. Systematic reviews are a core methodology in evidence-based health economics for judging medical effectiveness. In this work, the methodology was applied to provide objective evidence on the efficacy and safety of TAVI at 1-year follow-up and to assess whether TAVI confers a survival benefit compared with medical therapy.

METHODS

In accordance with the toolkit of the "German Scientific Working Group Technology Assessment for Health Care" (GSWG), a systematic literature review on the safety and efficacy of TAVI procedures was conducted in major bibliographic databases to identify all relevant publications. Preestablished inclusion criteria were defined. An initial screening of identified articles regarding titles and abstracts was followed by a full-text screening. Data from eligible articles were extracted and evaluated according to GSWG checklists followed by a qualitative synthesis of information.

RESULTS

The systematic literature search identified 12 primary publications (derived from 1,849 citations) for TAVI [number of patients (n) = 1,049] and 11 publications (derived from 189 citations) for medical therapy of AS (n = 946) that fulfilled the inclusion criteria. Mean overall procedural success rate for included TAVI interventions was 93.3%. Mean combined procedural, post-procedural, and cumulative in-hospital/30-day mortality was 11.4% (n = 116; range 5.3-23%). 1 year after TAVI, the mean overall survival rate was 75.9% (range 64.1-87%) compared with 62.4% (range 40-84.8%) for medically treated patients (p value < 0.01). 1-year survival after TAVI for patients treated with transvascular (TV) procedures was higher than after transapical (TA) procedures (79.2 vs. 73.6%) (p value = 0.04). At 1-year follow-up, the improved valvular function remained stable, and there was a trend towards an improved ventricular function.

CONCLUSION

Based on the best available data, in patients with symptomatic severe AS, TAVI demonstrates an improved 1-year survival compared with medical treatment. The survival benefit of TV-TAVI over medical therapy elucidated from this systematic literature review is +16.8% and therefore, in good congruence with the recently published results from the randomized PARTNER US trial (+20%).